The present specification describes systems and methods for detecting an occlusion in a tubing carrying a patient's blood through a manifold and into a dialyzer in a dialysis system. A controller measures pressures value of the blood at a predetermined point after exiting the manifold and before entering the dialyzer, calculates a historical running average, calculates a weighted sum of the most recent pressure values, and determines whether to trigger an occlusion alarm based on a function of the historical running average and the weighted sum of the most recent pressure values.